Fixing the dreaded “RFU Load Error/Send RFU Upgrade” on CP3505 Using a Mac

At work, I came upon a CP3505 LaserJet printer that was displaying this error message:

Naturally, I wondered why a perfectly good printer would get to this state. I power cycled the printer which revealed the true error:


I looked this error on Google, and found many other people in the same situation with no really good answers. This printer either needed a new formatter board or an RFU firmware update. I thought it would be simple enough to connect to the printer via FTP over the network and force the update, but I noticed that there was no activity displaying on the jetdirect port on the side of the printer. Sure enough, a ping to the printer resulted in lost packets.

At this point, I knew that I needed to directly connect to the printer using a USB cable since there were no other options (besides replacing the formatter board). Using Windows XP or Vista was unfortunately out of the question because I only had access to a Mac. Looking online, I couldn’t find a single resource in order to send a firmware file to the printer. I checked HP business forums, Google, and more with little to no results. After a little experimenting, I figured out what was needed to fix the printer using a Mac. These steps are similar to using a PC, but I found that a Mac was *much* easier after everything was said and done.

1. Get the firmware file from HP’s website. It’s usually in the “Cross operating system (BIOS, Firmware, Diagnostics, etc.)” category. When you visit that category, HP usually shows 3-4 links to firmware files (Mac, Windows, UNIX, etc). Secret here is that they are really all the same RFU firmware file, just compressed using different formats. Go ahead and down the one of choice and save it on your desktop or similar location.


2. Uncompress the files and remove the old compressed file since that will no longer be needed. Once again, I placed my file on the desktop, so I knew where it was.

3. Find a USB 2.0 cable (Type A to B) and plug that into your printer (while it’s on and displaying the error message). Then plug the other end to your computer. Nothing should happen on the computer side.

4. Next, go into the “Print and Fax” System Preferences control panel .


5. Click on the “plus” sign at the bottom left like you are installing a new printer.


6. In the add printer dialog box, make sure that the default icon is selected.


7. Then, you should see a printer in the list (only one in the list) called “HP LaserJet USB Upgrade”. If you do not see this printer (or any printer), you may have a bad cable, but most likely, you’re printer is toast. Click on HP LaserJet USB Upgrade, and your computer will try finding drivers for this type of printer (at this point, your computer has no idea what type of printer this is).

8. Go to “Print Using:” and select “Select Printer Software”.


9. When the list of printers come up, select an HP 4100 series printer driver. You may be wondering why you are choosing the HP 4100 series printer driver and your original printer driver. The answer is fairly simple, it really doesn’t matter what driver you choose except that it needs to the a certain kind that allows your computer to send a regular file to a printer for processing. Most of the HP drivers will do this, to be on the safe side, select the 4100.


10. Next, you’ll want to make sure it’s set as the default printer (you’ll see why in a minute). Although my picture shows that the printer is Offline, it should be Online if it’s still connected to the printer.


11. This next step involves using the terminal. Open the terminal by going to Applications>Utilities>Terminal. You can also perform a spotlight search for it.

12. Once the terminal window is up, type in “lpr” and then a space, and then type in the location of your firmware file, or drag and drop the firmware file (called “cp3505fw_03.020.3.rfu” in my case) on to the terminal window and the OS will do the rest. This command will print a file to the default printer which is why that was set earlier.


13. Press enter, and you should start to see a progress with the printer. Once the file is transferred over, the printer will power cycle and be ready for printing. All network settings should have remained intact. Enjoy! You can remove the printer we just created by clicking on the “-” sign in the print and fax system preference panel.

Extra: For you PC users (XP and Vista), the theory of sending the firmware is the same. The main differences is the dos console and how the printer is added to the system.

52 Replies to “Fixing the dreaded “RFU Load Error/Send RFU Upgrade” on CP3505 Using a Mac”

  1. Thanks for this! Searched for help everywhere, and everyone kept saying call HP, the IO board is bad. Your instructions worked, and revived our printer, days before it was going to be used in an important event! thanks!!!!

  2. Thank you very much, I followed your instructions to the letter and the HP CLJ3505 that just came up with the “RFU Load Error/Send RFU Upgrade” message is now up and working perfectly.

  3. Thanks…I wish I had seen this 6months ago when I went through this. After a whole day of fooling around I called HP, fooled around for another hour before they said I needed another motherboard. They send me one promptly and it turned out to be the wrong one. They sent another and that worked. now I wonder if indeed it needed to be changed at all.

  4. guys,

    please help me, i am having the same issue, but whenever i send the firmware to the printer, when i open the printer, the file is stuck on 64kb/30MB transfer. and its not moving from overthere. how can i transfer the file successfully?

    i already try all the steps above, and all others, and its keep stucking on that 64kb.

  5. This worked for me on an HP P4014n. I followed the steps, but I got a message on the printer that said, “UNSUPPORTED”. I unplugged the printer and plugged it back in and as soon as I did that the rfu download started and the process completed. Doing it with my Mac was way easier than the PC solution. Thanks for the info!

  6. I had the same problem as Alex, update stops at 64kb
    What I did was changing the printer settings:
    Port settings, disable two-way
    Advanced settings, print directly

    Then I used the HP firmware update program for windows and the CP3505 started updating.

  7. Thank you for posting this…you saved us! We almost spent $619 on a new formatting board. Glad we saw this first!

  8. Please, i have the same problem with alex. it keep stuck in 64 kb/23mb. if i change the advance setting of print directly, the hp firmware update became not responding. what should i do??? do you have other solution that i can use. it’s stress me out.

  9. To reply to the previous comment, your firmware is physically bad. When it attempts to load like that and can’t read all the memory, the formatter needs to be replaced. It’s a known HP defect.

  10. Thanks so much – did this using a PC running XP – I was basically doing the update the same way, but it wouldn’t send until I changed the printer type to something else – in this case an HP 4100. Why is that?

  11. Spot on instructions for sending the RFU file.
    However, now comes up with an error 68.1 Permanent Storage Full. It still seems to print out OK but says that the job cannot be stored – I’ll be investigating further but thanks for putting up such useful and clear guidelines

  12. I have also problems with a HP Laserjet 2420n after I ran the upgrade received in an e-mail with the text:

    Routine Driver Alert Jun 24 2010
    HP LaserJet 2400 Series Printer Easy Firmware Update Utility – Windows Operating System – (Must Read README Before Installing) (ver 08.113.0.I35128)
    Products: HP LaserJet 2400 Printer series
    OS: Windows,Other Legacy OS

    Description: HP LaserJet 2400 Series Printer Easy Firmware Update Utility – Windows Operating System, version 08.113.0

    I have the message “Downld file now RFU LOAD ERROR”. I have rerun the upgrade three times via the USB connection. I have deinstalled and reinstalled the printer. Nothing helps.

    Please, does anyone know of a kind of “set to factory default” kind of reset for the HP laserjet 2420n?

  13. Absolutely brilliant! Devin Collier you are a star. Moral of the story is HP should hire you, or HP should give up making printers!

  14. As a reply to the 2420 question, when you have a bad firmware, you’re really out in the dark until you can get that up and running again. Resetting a printer involves having a good working firmware. Your only other option is to buy a new firmware chip from HP (or other sources).

  15. I use to like HP products but I am indeed discouraged for sometime now when “down file now SEND RFU UPGRADE” appeared on my hp lasserjet CP3505n printer.

    What may do to get my printer back to normal? please made it known to me in a jeffy.
    Thank you and God bless you.

    1. This is the purpose of this post. Go ahead and follow the directions here to install an updated firmware on your printer.


    I was getting “unsupported file type” for whatever reason when doing the LPR command. I had to go into the printing system preferences, open up the printer created from this tutorial, deleted the LPR’s in que, and then un-paused the printer. Then it took the upgrade….

  17. Almost there but still won’t print. I still get the unsupported message. What are the LPR’s in que ( post above)

  18. Re-rfu upgrade for colour laserjet cp 3505n.

    influate failure, download rfu upgrade now as my printer’s problem. I took the instructions given to someone by your outfit which worked for him and did not work fopr me. It again appeared usb cable not recorgnised. When i tried other two cable the same story. But downloading and sending the file was not a problem since I was able to follow the your instructions. What next? disposing or other option?

  19. my office also have the same prob. it solve by following this method and follow #12 recomendation. thanks for the info. hp coz make life difficult.

  20. Having spent most of this Sunday afternoon on this exact problem I thought I should add my experience. I am actually a Printer Engineer specialising on HP and generally with this problem the HP fix is to replace the Formatter.

    This was not an option with this particular machine so I set my mind to resolving the issue. My attempts to correct it via Windows failed at all steps and by chance I happen to have a Macbook mainly used by the kids for Skype sessions. I decided to try the Mac process but ultimately even that was unsuccessful but I learnt a few things along the way and am sure this is what finally helped me fix it.

    My Mac knowledge is almost nil, and one of the first things I encountered was a ‘permission denied’ error everytime I attempted the step at the Terminal. The cause will probably be obvious to those familiar with the Mac GUI but turned out to be simply that I’d overlooked extracting the downloaded file. Of course in Windows a compressed file is very clear but I didn’t recognise it as such. Duh. Having corrected that I then simply encountered a string of errors after executing the command, which I can’t now describe exactly but either way the file would not send to the printer.

    What I did find however was that each time I tried to send the file, it would only attempt it once, further attempts would do nothing. If I cycled the CP3505 printer power, the Mac would change the status from Ready to Offline and this was enough to convince me that the Printer was sound and that there was communication established but as soon as I tried to send the file, communication would then be lost.

    I was not able to find where to adjust the port settings as described, no matter where I looked I could not find them (using Max OS X 10.6.8).

    I decided to go back to Windows after reading this article….

    … mainly because I understand Windows at a hardware level much better than Mac.

    Anyway, to cut a loooong story short, I believe the Printer for some reason was disconnecting or hanging after a failed attempt. Everytime I cycled the printer power I could get another attempt.

    In the end, I sent the firmware upgrade and then cycled the printer power once again – this time round (and this is after something like 30 or 40 previous attempts) as soon as the printer would normally have brought up the “Send RFU upgrade” error it started receiving the file and sucessfully restarted. Fantastic.

    Interesting to note that in the link above, it is recommended to name the newly installed driver EXACTLY as “Hewlett-PackardHP LaserJet USB Upgrade” and the changes to bi-directional printing and printing direct to the port (bypassing the windows spooler).

    I wish I had documented all my steps better was frankly I was about at the point of giving up but glad I persisted. Of course if a client had been paying for all the time it probably would not be economic but I wanted to see it through and the experience will come in useful for further similar problems which will take much less time.

    Good luck – one way or another, this process works, you might just have to be a bit imaginative.

  21. Thanks a lot! i should have gotten the macbook the minute i read your post. would have saved me 3 hours trying to get it to run on windows.

  22. I tried using LPT Port.The RFU file was received by printer it showed 100%. Then it displayed message power cycling,it taking too much time,I restarted it manually and there was no do i need to replace formatter.

  23. This evening I managed to fail to update my P3305D firmware using Snow Leopard, having done it 3 times before in Tiger and Leopard. There it was, unable to complete its boot sequence, and the Mac wouldn’t see it because it hadn’t completed its boot seq….

    So many other sites suggest sending off for a formatter card, but your solution worked like a dream (well, OK, like a second dream – the first time, the Mac tried to interrogate the printer for options, and it wasn’t going to answer!).

    Your instructions are clear and a real life-saver.

    Thank you so much. If you come over to the UK, I’ll buy you a pint!

  24. hello there and thank you to your information ? I’ve definitely picked up anything new from here. Well I am adding this RSS to my e-mail and can look out for much extra of your respective intriguing content. Ensure that you update this once more soon..

  25. FYI. I didn’t see this post while wasting half a day trying to update my RFU. I gave up but I tried a new memory stick in the printer the next day……message went away and printer worked instantly.

  26. Thanks for this, it was very helpful! A note for users of linux: you may have to pass lpr the -oraw option (or uncomment the appropriate line in /etc/cups/mime.convs) to permit lpr to print raw files like the rfu, otherwise you may see something like:

    lpr: Unsupported format ‘application/octet-stream’!

    Thanks again, this really got me pointed in the right direction!

  27. Excellent support!!!!

    I installed upgrade via a Mac. After the first try I also got the “unsuppoted file type” message. As recommended by Marcus I went to printing system preferences, deleted the LPR’s in que, and then un-paused the printer. Then it took the upgrade and is working : ) thx

  28. Hello, I have followed all the steps, and after I add the rfu file, I get a bunch of error messages at the command prompt. IE:

    /Users/ccleesmith/Desktop/ljCP3505fw_03.130.2.rfu: line 1: -12345X@PJL: command not found
    : command not foundesktop/ljCP3505fw_03.130.2.rfu: line 2: -12345X@PJL
    /Users/ccleesmith/Desktop/ljCP3505fw_03.130.2.rfu: line 3: @PJL: command not found
    /Users/ccleesmith/Desktop/ljCP3505fw_03.130.2.rfu: line 4: @PJL: command not found
    /Users/ccleesmith/Desktop/ljCP3505fw_03.130.2.rfu: line 5: @PJL: command not found
    /Users/ccleesmith/Desktop/ljCP3505fw_03.130.2.rfu: line 6: @PJL: command not found
    /Users/ccleesmith/Desktop/ljCP3505fw_03.130.2.rfu: line 9: syntax error near unexpected token `(‘
    /Users/ccleesmith/Desktop/ljCP3505fw_03.130.2.rfu: line 9: ` NuNqNqNqNqNq 9@g?pE#?@H?y@H

    Anyone else able to resolve this? Or point me in the right direction?


  29. Perhaps I was lucky. I powered off our CP3505 and switched it on whilst pressing the Green button. Recalibrated and came up perfectly.

  30. I had this problem at work today, networked CP3505 to Windows 2003 server. Perhaps I was lucky, but I fixed it by powering on the printer whilst pressing the green OK/Tick button. This must have forced a reload from the server I guess, but the printer came up fine.

  31. does anybody has this steps on Windows XP,
    am able to get until step but once there got lost, my .rfu icon looks weird and not able to make “lpr” command works on “cmd”
    please help,

  32. This is great!! I do want to point out that after I installed the HP LaserJet USB Upgrade my printer was displaying UNSUPPORTED and would not adjust. So I turned it off then on again (while keeping the Upgrade as the default printer) and then wrote the code in terminal and it worked. Thank you for this rock!

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